Graduate Student Univ. of Texas, San Antonio, United States
Disclosure(s):
Raghad Said: No financial relationships to disclose
Introduction/Rationale: Endometriosis involves the ectopic growth of endometrial-like cells, often in the ovaries and peritoneal cavity, leading to pain and infertility in many patients. Chronic inflammation plays a central role in endometriosis pathogenesis. Upon interrogation of an endometriosis scRNA sequencing dataset, we found IL32 to be one of the most highly expressed cytokines in endometriosis compared to eutopic endometrium and unaffected ovary tissues. IL32 is an understudied cytokine elevated in several inflammatory diseases. In some contexts, IL32 positively regulates production of IL1α, IL1β, IL6, TNFα, and IL8, but its specific role in endometriosis is unknown.
Methods: To establish the effect of IL32 on immune cells, we tested unstimulated, IL32-treated, stimulated, and stimulated+IL32 conditions on whole human PBMCs in 18hr cultures, and sorted human PBMCs in 7-day cultures. Cytokine expression was measured using RT-qPCR. Proliferation, viability, and activation markers were quantified using flow cytometry.
Results: IL32 treatment induced a 200-fold increase in IL1β expression and a 12-fold increase in IL6 expression. This increase was dampened but remained significant in stimulated cells. 7-day treatment with IL32 did not affect differentiation of T, B, or NK cells. However, viability of unstimulated T cells was increased 3.4-fold, with similar effects on B (1.7-fold), NK (1.5-fold), and myeloid cells (2.6-fold). Notably, IL32 increased the viability of stimulated myeloid cells 6-fold, whereas other stimulated immune cell types were unaffected.
Conclusion: Inflammatory IL32-inducible cytokines are highly transcribed in endometriosis M2 macrophages. We hypothesize that IL32 contributes to endometriosis pathogenesis by inducing inflammatory cytokine production and cell survival in macrophages, possibly through the regulation of NFkB signaling. Our ongoing research is focused on deciphering the downstream targets of IL32 through CITE-seq profiling of IL32-treated cells.
